Shrews II

White-toothed shrews (Crocidurinae)

Class Mammalia

Order Insectivora

Family Soricidae

Subfamily Crocidurinae

Thumbnail description
Small mouse-like mammals with long pointed snouts, white teeth, short legs, and small eyes

Size
1.3–5.3 in (3.5–13.5 cm); 0.06–1.5 oz (2–40 g)

Number of genera, species
11 genera; 212 species

Habitat
Typically in moist habitats that are rich in invertebrate prey; can also be found in habitats ranging from arid regions to tropical forests

Conservation status
Critically Endangered: 16 species; Endangered: 16 species; Vulnerable: 36 species; Lower Risk/Near Threatened: 7 species; Data Deficient 6 species

Distribution
Throughout the Old World, found in many African countries, much of continental Europe and southeastern Asia

Evolution and systematics

Among the most ancient of all living animals, shrews have remained almost unchanged over the past 45 million years. This ancient family diverged from other insectivores before the Eocene period, with modern genera (subfamilies Crocidurinae and Soricinae) first appearing in the Miocene in Europe. Soricids later migrated to Africa and North America. The taxonomic status of modern shrews (Soricidae) is currently undergoing a significant overhaul due to considerable recent taxonomic research on the genetics, morphology, ecology, and behavior of shrews. At present, the shrew family is divided into two living subfamilies, the Crocidurinae and the Soricinae. The members of the subfamily Crocidurinae, white-toothed shrews, are further subdivided into 11 genera (Crocidura, Diplomesodon, Feroculus, Myosorex, Paracrocidura, Ruwenzorisorex, Scutisorex, Solisorex, Suncus, Surdisorex, and Sylvisorex). Current generic boundaries are based on very few characters. The delimitation of some genera of the subfamily Crocidurinae is still the focus of considerable genetic and morphologic research.

The genetic distances between different genera of Crocidinurae based on allozyme variation generally support a sub-division of the living species into these genera. Those species of Crocidurinae that have been studied to date show considerable chromosomal and genetic differentiation. Karyotypic and protein electrophoresis studies have been very helpful in identifying many sibling and cryptic species that were difficult to recognize by conventional methods.

Crocidurinae includes the genus Crocidura, which has 151 species—the largest number of living species of any placental mammal genus.

Physical characteristics

Shrews are the smallest of the insectivores. All shrews have short legs, five claws on each foot, short dense fur, small external ears, an elongated, pointed snout with long tactile hairs (vibrissae), and most have relatively long tails. All have extremely small eyes (often hidden in the fur) and relatively poor eyesight, but the sense of smell is keen, as suggested by their long, mobile snouts. The external ears are reduced in some species and usually hidden in their fur. Hearing is acute. The fur is short, dense, and usually some shade of brown or gray. The skull is long and narrow and has no zygomatic arch. The shrew has one of the most primitive brains of all placental mammals; the brain is small and smooth, dominated by large olfactory bulbs. The dentition is unlike any other family. The very large upper and lower incisors slant forward and meet like forceps. The external genitals of some species are enclosed in a fold of skin. Some species have a venomous saliva. Shrews have skin glands and genital or marking glands that secrete a substance with an unpleasant musky odor. The foot is not specialized, except in some aquatic species.

Members of the white-toothed shrew (Crocidurinae) subfamily are initially distinguished from their red-toothed (Soricinae) counterparts by the color of the enamel of the tips of their incisors. Red-toothed shrews have red teeth due to red pigmentations, and white-toothed shrews lack pigmentation. The two exceptions are Chimarrogale and Nectogale, two white-toothed aquatic species placed in the red-toothed subfamily.

Crocidurinae are also characterized by the retention of primitive dental characteristics. Modern forms differ from those of the later Miocene and from one another by the loss of one, two, or three upper and lower antemolars; reduction in the talonid of the lower third molar and greater emargination of the posterior basal outline of the upper premolar and upper first molar. The first set of teeth is shed in the embryonic stage, so that the teeth at birth are the permanent set. Crocidurinines have 26–32 teeth, normally six on each side of the lower jaw.

Differences in physiology, brain anatomy, and morphology are also diagnostic for this subfamily, including the articulation of the mandibular condyle and the position of the mental foramen. The two bones of the lower leg are fused. The cerebrum is less highly developed in the white-toothed shrews than the red-toothed shrews.

There is considerable anatomical variation among genera of Crocidurinae. Suncus etruscus of southern Europe has a body mass of approximately 0.07 oz (2 g), making it one of the smallest mammals known. One of the largest true shrew representatives of the subfamily Crocidurinae is Suncus murinus, with a head and body length of 6 in (15 cm) and weight of 1.0 oz (30 g) for males and 0.7 oz (20 g) for females.

Myosorex is considered the most ancient of the living genera because it has the largest number of teeth. Suncus differ from Crocidura by retention of a fourth upper antemolar. Sylvisorex differ from both Suncus and Crocidura by a lack of tail bristles, and differ even more from Crocidura by the retention of a fourth upper antemolar. In most genera, the genital and urinary systems have a common opening though the skin. Myosorex has an independent urinary tract system.

There are also significant differences in brain development between genera within the Crocidurinae subfamily. Members of Crocidura show more brain development than members of the thick-tailed shrews of the genus Suncus.

Distribution

The subfamily Crocidurinae is Paleotropical in origin; the white-toothed shrews originated in the Old World tropics and radiated across Africa, Europe, and Asia. This is reflected in the pattern of present day Crocidurinae distribution. Some species of Crocidurinae live in arid regions and semideserts.

Habitat

Crocidurinae shrews usually inhabit damp and dry forests, grassland, cultivated areas, and occasionally human settlements and buildings. Some white-toothed shrews in the

Diplomesodon and Crocidura genera live in arid areas and semi-deserts. They are mainly terrestrial, but some take to water freely, and others burrow a little. They are usually abundant wherever there is sufficient ground vegetation to provide cover. They occur over a great altitudinal range and in many kinds of plant communities. Most species prefer moist habitats, but some species are also found in arid regions.

Behavior

Shrews are extremely active, nervous animals. Some are active day and night, others only at night. When frightened, their heart may beat at a rate of 1,200 times per minute. Shrews have been known to die from loud noises, even thunder. Experiments with oxygen consumption suggest that shrews have a higher metabolic rate than mice of similar size. They are active throughout the year, though some go into torpor.

Some genera of Crocidurinae are notably aggressive and voracious. Shrews have been known to fight to the death. It is widely believed that most of these cases occurred during famine, when shrews may have become cannibalistic. The chirping and buzzing vocalizations sometimes heard are thought to be aggressive signals, and shrews may emit a squeak when alarmed or threatened.

Most shrews are solitary, except when they pair off during breeding. Members of Suncus and Crocidura can be tolerant of other shrews of the opposite gender during mating. After a period of initial fighting, a pair may live together. Once the pair bond has formed, the parent shrews may share a nest. Pairs from some species, such as Crocidura russula, have been observed building nests together.

Shrews are often territorial and have relatively small home ranges (0.1–0.25 acres [0.04–0.1 ha]) that vary in size with seasons of the year and with the timing of the animal's mating season. Shrews mark their territories with their scent glands. Data on population densities are limited to a few species. The population densities of shrews varies considerably between species. The recorded population density of the lesser whitetailed shrew on Corsica is 1.9–5.3 animals per hectare.

White-toothed shrews can dig their own burrow but often use those of other animals such as woodmice or molerats. They can tunnel through loose humus and leaf mold and often are active under fallen trees and heaps of brushwood or stone.

Feeding ecology and diet

Shrews are primarily insectivorous and carnivorous, but will eat some plant materials such as seeds and nuts. Considering their high energy needs, it is likely that shrews need to adapt their diet according to food availability throughout the year. Their diets may include frogs, toads, and lizards. In captivity, many species will consume all but the skin, tail, and parts of the limbs of a small mammal; the brain is always eaten first. If no other food is available, some species resort to cannibalism.

The common belief that shrews cannot survive without eating every few hours is not a rule. In some Crocidurinae species, animals are able to lower their body temperatures in response to food scarcity. This is an example of food deprivation triggering torpor, a state of reduced activity level. This energy-saving state permits the animal to survive difficult conditions temporarily. For example, Savi's pygmy shrew (Suncus etruscus) loses 10–15% of its body weight by day, then increases food consumption at night to make up the loss. If food is scarce, the shrew may enter torpor.

Some species of shrews have salivary glands that secrete a poisonous substance that usually immobilizes the prey. There are records of shrew bites to humans that caused great pain. There is some question over whether the saliva of Savi's pygmy shrew is poisonous. These diminutive shrews need to bite their prey only once to subdue them.

Reproductive biology

In the tropics, shrews form monogamous pairs and breed throughout the year, while those living in northern temperate zones usually breed from March to November. The known gestation periods are 17–28 days. There are one or several litters a year with 2–10 young in each litter. The young are born naked and blind in a nest of dried grass or leaves placed under a shelter or in a ground cavity. Weaning appears to occur at 2–4 weeks in most forms. Some zoologists estimate the life span in the wild to be 12–18 months, possibly longer. The oldest known Crocidurinae lived approximately four years.

Among Crocidurinae, the young are hairless for the first week and fully haired at 16 days. The auditory canals of Crocidurinae species open between the fifth and ninth days of life and the eyes open between the thirteenth and fifteenth days. Crocidurinae species begin to wean their young after 20–22 days. The young are practically adults and are sexually mature by 2–3 months.

Within the Crocidura, gestation is 27–31 days; litter size varies from one to 10. Larger litter sizes are associated with higher energy demands on the mother. The young weigh about 0.04 oz (1 g) at birth and are weaned at around 20 days. In Crocidura russula, young females can conceive at approximately 30 days of age.

Some Crocidurinae species and at least one Sorex species, display an unusual caravan behavior. The mother initally carries the young infants in her mouth. Starting on the sixth to tenth day, depending on the species, the mother and her young move in a caravan. At the slightest suspicious sound, one of the baby shrews grasps its mother's fur near the base of the tail. A second shrew grabs onto the first, a third onto the second and so on until the whole litter is lined up behind the female who then pulls her train of offspring.

Conservation status

The greatest threat for the Crocidurinae shrews is environmental disturbance and pollution. Loss of forest habitats has a considerable effect on forest-dwelling species.

Data on the conservation status of most Crocidurinae shrew species are limited due to a paucity of population research. The Crocidurinae shrews included in the 2002 IUCN Red List often belong to very rare and endemic species with restricted distribution and low population densities. Some of the threatened species are only known from the locality of their original description. There is an urgent need for considerable research on most shrew species.

Significance to humans

Shrews may be valuable to agricultural communities as a form of natural control of insect pests due to their consumption of large numbers of insects and insect larvae. They also play a significant role in increasing the rate of litter decay.

Shrews are frequently used for neurological research and in other areas of biomedicine and evolutionary biology. They can also serve as useful indicators of environmental contamination such as heavy metals. Shrews feeding on earthworms in areas with heavy metals in the soil can accumulate significant levels of heavy metals in their tissues.

Species accounts

List of Species

Common European white-toothed shrew

Crocidura russula

taxonomy

Crocidura russula (Hermann, 1780), Bas Rhin, France.

other common names

French: Musaraigne musette; German: Hausspitzmaus.

physical characteristics

Head and body length 2.4–3.4 in (6.1–8.6 cm); tail 1.2–1.7 in (3.0–4.3 cm); weight 0.2–0.4 oz (6–12 g). Grayish brown to reddish brown with a silverly luster on its back. The flanks and underside are brownish. The tail is brown on the dorsal surface and gray on the underside with long protruding hairs. The ears are visible. It has 28 completely white teeth (including three upper unicuspids). This species is considered to be more advanced than many other Crocidurinae genera.

distribution

Occurs in Morocco, Algeria, Tunisia, southern and western Europe including an Atlantic island off of France, and on the Mediterranean islands of Ibiza, Sardinia, and Pantelleria.

habitat

Lives in or near farmyards, yards, fields, and at the edges of cities. Close to the Mediterranean, these small shrews are found in brushlands, in the underbrush of cork and in olive groves and the overgrowth of vineyards.

behavior

Generally aggressive and voracious. When provoked, they frequently crouch on the ground with head raised and emit a squeak. This species is more tolerant of conspecifics. During the cold of winter, individuals may share nests. With onset of spring, mature females resume their territorial behavior.

feeding ecology and diet

Their diet consists of invertebrates and the bodies of freshly killed animals. In captivity, the species will consume all but the skin, tail, and parts of the limbs of a small mammal; the brain is always eaten first. They also feed on frogs, toads and lizards.

reproductive biology

Gestation lasts 27–30 days. Litter size varies from three to eleven young. At birth, young weigh 0.02–0.03 oz (0.8–0.9 g). The young open their eyes at 13 days. They are hairless for the first week and fully haired at 16 days. After weaning at around 17–22 days, the young are practically adults, ready to become independent. Young females of this species can conceive at approximately 30 days of age. The expected life span for this species is 34–38 months.

Common white-tooth shrew mothers and young have been observed in caravan, a behavior where a young shrew offspring of six days or older grabs onto the back of its mother, and other young shrews from the litter form a line of shrews by latching onto each other. May form monogamous pairs for breeding.

conservation status

Not threatened.

significance to humans

None known.

Savi's pygmy shrew

Suncus etruscus

taxonomy

Suncus etruscus (Savi, 1822), Pisa, Italy.

other common names

English: Pygmy white-toothed shrew; French: Pachyure etrusque, musaraigne etrusque; German: Etruskerspizmaus.

physical characteristics

Head and body length 1.4–2.1 in (3.6–5.3 cm); tail 0.8–1.2 in (2.1–3 cm). One of smallest mammals in the world; smallest in Europe. Grayish brown dorsal side, blackish brown or ash-gray ventral side. Ears clearly visible. Thirty completely white teeth. Individual long hairs on the tail.

distribution

Mediterranean to India and Sri Lanka. Includes southern Europe, northern Africa, Arabian Peninsula and Asia Minor to Iraq, Turkmenistan, Afghanistan, Pakistan, Nepal, Bhutan, Myanmar, Thailand, and Yunnan (China).

habitat

Lives in old vineyards, olive groves, brushwood yards, cultivated land with low rock walls, dumps, rock piles.

behavior

Considered solitary and intolerant of each other. Their repertoire of vocalizations, made up of chirps and buzzes are regarded as aggressive signals. However, in the laboratory, pairs and young of this species have been observed living peacefully together during breeding season.

feeding ecology and diet

Nothing known.

reproductive biology

In laboratory studies the gestation for Suncus etruscus has been recorded as 27.5 days. Litter sizes of 4–6 were observed in Pakistan while smaller litters of 2–5 offspring have been recorded in captivity. Presumably monogamous when breeding.

conservation status

Not threatened.

significance to humans

None known.

Forest musk shrew

Sylvisorex megalura

taxonomy

Sylvisorex megalura (Jentink, 1888), Junk River, Schieffelinsville, Liberia.

other common names

English: Climbing shrew.

physical characteristics

Head and body length 1.8–4 in (4.5–10 cm); tail 1.5–3.5 in (4–9 cm); weight 3–0.42 oz (12 g). Soft, velvety fur usually longer than that of Suncus. Lack long tail hairs. Upperparts are usually slate gray and underparts are slightly paler.

distribution

Tropical forest zone of Africa, from upper Guinea to Ethiopia, and south to Mozambique and Zimbabwe.

habitat

Inhabit deep forests. Individuals have been observed climbing in trees and in grasslands well away from trees.

behavior

Solitary animal that has been found active during the day and at night.

feeding ecology and diet

Nothing is known.

reproductive biology

Nothing is known.

conservation status

Not threatened.

significance to humans

None known.

Piebald shrew

Diplomesodon pulchellum

taxonomy

Diplomesodon pulchellum (Lichtenstein, 1823), eastern bank of Uraal River, Kazakhstan.

other common names

None known.

physical characteristics

Head and body length 3.5–5.0 in (9.0–12.5 cm); tail 3.5–4.5 in (8.9–11.0 cm). The piebald shrew has a striking color pattern; fur is grayish with an elongated patch of white fur at the nape of the neck. Underparts, feet and tail are white. All hairs are gray at the base. It has fringes of long, supple hair on the soles and toes of the forepaws and hind paw. These fringes increase the support surface of the paws of this sand-dwelling species and facilitate its movement on the sand. The ears are comparatively large.

distribution

Inhabits desert environments within Turkmenistan, Uzbekistan, and southern Kazakhstan (between Lake Balkhash and the Volga River).

habitat

Inhabits the sandy soil of semideserts.

behavior

The piebald shrew is active throughout the year, primarily at night, but sometimes during the day. It is able to dig through sand quickly.

feeding ecology and diet

Primarily consumes lizards and insects. Observed killing lizards by biting the head in captivity. The shrew consumed all parts of the lizard, including the skull and skeleton, but left the feet and tail. When eating insects, only the chitin is not consumed.

reproductive biology

Nothing is known, but probably monogamous when breeding.

conservation status

Not threatened.

significance to humans

None known.

Forest shrew

Myosorex varius

taxonomy

Myosorex varius (Smuts, 1832), Cape of Good Hope, South Africa.

other common names

English: Mouse shrew; French: Musaraigne des bois africaine; German: Sudafrikanische Waldspitzmaus.

physical characteristics

Head and body length 2.8–3.8 in (7.2–9.5 cm), tail 1.2–2 in (3.1–5 cm), weight 0.3–0.7 oz (7–19 g). Dorsal side is brown; ventral side, somewhat lighter, tail relatively short; eyes small; ears reduced. Distinguished by its first upper incisor, which is enlarged and has a hook at the end. This tooth also has a cusp projecting ventrally at the base.

distribution

South Africa, from northwest Cape Province to eastern Transvaal; Lesotho and Orange Free State.

habitat

Moist areas, usually in forests, scrub, or other dense vegetation along the banks of open and forested streams.

behavior

Diurnal and nocturnal, active throughout the year. Members of this genus are primarily solitary except during the breeding season. However, males and females have been observed eating and sleeping together after a period of avoiding each other, aggressive squeaks and/or brief fighting.

feeding ecology and diet

Various invertebrates including insects, snails, spiders, centipedes. Small birds and mammals when available.

reproductive biology

Usually monogamous. Litter size is two to five. Weight at birth is 0.03 oz (1 g). Wean young at 20–22 days. Life span averages 12 months.

conservation status

Not threatened.

significance to humans

None known.

Armored shrew

Scutisorex somereni

taxonomy

Scutisorex somereni (Thomas, 1910), Kyetume, Uganda.

other common names

English: Hero shrew; French: Musaraigne cuirassee, musaraigne armee; German: Schildspitzmaus.

physical characteristics

Head and body length 4.8–6in (12–15 cm); tail 2.7–3.8 in (6.8–9.5 cm); weight 1.1–3.2 oz (30–90 g). Long thick gray fur with thin, chamois-colored streaks. Distinguished by a unique spine having almost double the number of vertebrae of other shrews. The vertebrae have lateral interlocking spines in addition to dorsal and ventral spines. This spine structure may provide

considerable strength to the back, without limiting dorsal, ventral and lateral flexibility. Other characteristics include a naked tail, 30 completely white teeth, and four teats.

distribution

Tropical rainforests of the Zaire Basin and adjacent mountains in Uganda, Rwanda, and Burundi.

habitat

Edges of gallery forests; in fallen leaves and in swampy regions.

behavior

The armored shrew is active both night and day.

feeding ecology and diet

Feeds on small mammals when available as well as insects and some plant matter.

reproductive biology

Probably monogamous. Small litters with one to three offspring.

conservation status

Not threatened.

significance to humans

None known.

Pearson's long-clawed shrew

Solisorex pearsoni

taxonomy

Solisorex pearsoni Thomas, 1924, Central Province, Sri Lanka.

other common names

French: Pachyure aux longues griffes; German: Pearsons Langkrallenspitzmaus.

physical characteristics

Head and body length 5–5.4 in (12.5–13.4 cm); tail 2.4–2.6 in (5.9–6.6 cm). The fur is soft, dark gray along the back with a lighter lustrous underside. Its small ears are fully furred and hidden in fur. Teeth are large and heavy and the anterior incisors are well developed. Claws on the forefeet are very long. The slender tail is closely haired and lacks the scattered long hairs. Twenty-eight completely white teeth.

distribution

Restricted to the central highlands of Sri Lanka, from an altitudinal range of 3,609–6,070 ft (1,100–1,850 m).

habitat

This species is reported to inhabit virgin forest though some individuals have been trapped in long grass.

behavior

Nothing is known.

feeding ecology and diet

Feeds on invertebrates and vertebrates.

reproductive biology

Nothing is known.

conservation status

Endangered. S. personi is restricted to a small area of declining habitat that is being altered by human encroachment.

significance to humans

None known.

Schouteden's shrew

Paracrocidura schoutedeni

taxonomy

Paracrocidura schoutedeni Heim de Balsac, 1959, Kasai, Democratic Republic of the Congo.

other common names

French: Musaraigne a dents blanches du Congo, musaraigne a dents blanches de Schouteden; German: Schildspitzmaus.

physical characteristics

Head and body length 2.6–3.8 in (6.5–9.5 cm); tail 1.4–1.7 in (3.4–4.4 cm); weight 0.3–0.7 oz (10–20 g). Short, fine, black fur, small ears covered with fine fur, short limbs, short claws. The tail has short hair with some long hairs. The teeth are completely white. Paracrocidura is identified as a separate genus on the basis of its distinct dental characteristics. It has 28 white teeth, of which three are maxillary unicuspids. An unusual feature is the straightness of the posterior borders of the fourth premolar and first and second molars, and the development of the first premolar. It also has aliform processes at the inner edge of the upper incisors and a bicuspid second lower premolar.

distribution

Occurs in the lowland primary forests in south Cameroon, Gabon, Democratic Republic of the Congo, and in Central Africa Republic.

habitat

Lowland rainforests.

behavior

Nothing is known.

feeding ecology and diet

Nothing is known.

reproductive biology

Litter size is small, one to three young.

conservation status

Not threatened.

significance to humans

None known.

Ruwenzori shrew

Ruwenzorisorex suncoides

taxonomy

Ruwenzorisorex suncoides (Osgood, 1936), Kalongi, Democratic Republic of the Congo.

other common names

None known.

physical characteristics

Head and body length 3.6–3.74 in (9.2–9.5 cm); tail 2.2–2.5 in (5.5–6.2 cm); weight 0.64 oz (18.2 g). Shiny black fur with paler sides and feet. Stocky body and short head. Hind feet are long. The tail is almost naked and has no long hairs. The external ears are small and round. Primarily distinguished by cranial and dental features. The skull is relatively flat and rectangular in profile. The first lower molar is massive.

distribution

Endemic to the Albertine Rift, occurring from the Ruwenzori Mountains (Uganda), eastern Democratic Republic of the Congo, Burundi and Rwanda.

habitat

Damp, mossy mountain forests. All specimens have been found at elevations of 2,625–6,890 ft (800–2,100 m).

behavior

Comparatively social as indicated by the presence of multiple shrews nesting together.

feeding ecology and diet

Nothing known.

reproductive biology

There is some indication that Ruwenzori shrews breed twice a year. Probably monogamous when breeding

conservation status

Vulnerable.

significance to humans

None known.

Kelaart's long-clawed shrew

Feroculus feroculus

taxonomy

Feroculus feroculus (Kelaart, 1850), central mountains, Sri Lanka, at altitude of 6,000 ft (2,000 m). Initially, this species was identified as a water shrew; more recently identified as a separate species (semi-fossorial).

other common names

French: Pachyure aux longues griffes; German: Kelaarts Langkrallenspitzmaus.

physical characteristics

Head and body length 4.2–4.7 in (10.6–11.8 cm); tail 2.2–2.9 in (5.6–7.3 cm); 1.2–1.3 oz (35–37 g). Known from only a few specimens. The back is slate black, underside is lighter, dark tail with a few whitish hairs at the tip and some individual long hairs, and the forefeet are off-white. It has 30 completely white teeth.

distribution

Endemic to central mountains of Sri Lanka.

habitat

Observed among weeds and other dense undergrowth in wet ravines. Primarily along hillsides of the central mountains of Sri Lanka. It appears to be confined to valleys and slopes of the central mountain range of Sri Lanka at elevations between 5,550 and 6,450 ft (1,850–2,150 m).

behavior

Very little is known about the behavior of this species.

feeding ecology and diet

Feeds on invertebrates, vertebrates and plant material.

reproductive biology

Nothing is known.

conservation status

Endangered. Decline of this species may be due to encroachment of humans on its limited habitat.

significance to humans

None known.

Resources

Books

Corbet, G. B., and J. E. Hill. The Mammals of the Indomalayan Region: A Systematic Review. Oxford: Oxford University Press, 1992.

IUCN. Eurasian Insectivores and Tree Shrews—Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN, 1995.

Merritt, J. F., G. L. Kirkland, and R. K. Roberts, eds. Advances in The Biology of Shrews. Pittsburgh: Carnegie Museum of Natural History, Special Publication 18, 1994.

Mitchell-Jones, A. J., et al. The Atlas of European Mammals. London: Poyser Natural History—Academic Press, 1999.

Wilson, D. E., and S. Ruff, eds. The Smithsonian Book of North American Mammals. Washington, DC, and London: Smithsonian Institution Press, 1999.

Wójcik, J. M., and M. Wolsan, eds. Evolution of Shrews. Bialowieza: Mammal Research Institute, Polish Academy of Sciences, 1998.

Organizations

IUCN Species Survival Commission, Insectivore Specialist Group, Dr. Werner Haberl, Chair. Hamburgerstrasse 11, Vienna, A-1050 Austria. Phone: +4315861094. Fax: +4315861094. E-mail: shrewbib@sorex.vienna.at Web site: <http://members.vienna.at/shrew/itses.html>

Corliss Karasov